Cell surface ectoATPase and ectoprotein kinase have been isolated as shed material in oviductal secretions. The ATPase binds to the surface of the freshly ovulated oocyte. The protein kinase enhances calcium uptake in sperm. Antibodies have been prepared against both enzymes. Enzymes will be purified further by ion exchange, hydrophobic and affinity chromatography and monoclonal antibodies will be prepared. Antibodies against ectoATPaxe will be studied using radiobinding assays to determine whether changes occur during malignant transformation of certain types of cells. Antibodies against protein kinase will be studied to determine their use in inhibition of calcium uptake by sperm and subsequent inhibition of the acrosomal reaction necessary for fertilization.